To measure voltage and current, for example, in power supply circuits, a shunt resistor is coupled with a measurement device, e.g., a sense (measurement) resistor and a sense amplifier coupled to the sense resistor. The higher voltage node of the sense resistor may be called “VBUS” and the voltage node on the load side of the sense resistor may be called “VSENSE.” The sense amplifier may also include sampling circuits in the analog front-end circuits. Such devices may be combined with a microcontroller having an analog-to-digital converter (ADC). The microcontroller usually operates at a low voltage and, hence, most of its surrounding support circuits are also designed for such a low voltage, for example, 3.3 or 5 VDC. The power supply circuit, however, often generates a much higher voltage and measuring the current on the high side introduces a high common mode voltage. Using such a measurement circuit to determine the current in a high voltage circuit may, therefore, require a special sampling circuit. Sampling of a high voltage signal with a multiplexer-capable sampling architecture is often desired while not consuming significant power from the input source and not requiring a high-voltage supply. A high voltage in such a scenario may be a voltage of up to about 40 VDC, but up to about 70 VDC is anticipated in the near future.